The present invention relates generally to a protective copolymer coating, and, more particularly, to a protective copolymer coating which can be removed by an alkaline aqueous solution.
It is customary to use a protective coating on new products when transporting them or otherwise exposing them to the elements. An ideal protective coating must dry rapidly, have the strength to protect the surface of the product from the elements, and be easily removed.
Prior coatings have not had all of the foregoing properties. Rapid drying has been achieved by using a coating with a low acidity. However, the lower the acidity, the more difficult it is to remove the coating with an alkaline aqueous solution. The strength of the coatings is improved when it has a high glass transition point, but this also limits the ease of removing the coating with an alkaline aqueous solution. A coating with a high acidity and a low glass transition point is more readily removable with an alkaline aqueous solution, but it does not dry rapidly and is not very strong. This is the problem with the coating in Japanese Laid-open Patent Publication No. 62-253673. This patent discloses a protective coating of alkyl acrylate, alkyl methacrylate, .alpha., .beta.-ethylenically unsaturated carboxylic acid, and .alpha., .beta.-ethylenically unsaturated monomer that can be removed by an alkaline aqueous solution.